What are you doing that's giving these kinds of speeds?
Things that can slow down the transfer rate:
If you're transferring a lot of small files, you'll find the speeds are a lot slower than if you transfer just a few very large files.
If you're transferring to or from a slower device (a USB device, for example) then it will limit the transfer rate.
If you're transferring files from one place to another on the same drive, then speeds will be very slow because the head has to move back and forth. Note if you have two partitions (C: and D: for example) on the same drive, then transfers between them will also be much slower.
If there's other concurrent activity occurring on the source or target drive, that will also slow things down.